I wouldn't necessarily say she's having multiples, however, I'm not sure that she isn't either. Often times HCG levels will be really high with multiples, but I've also seen really high levels that are just one baby. An HCG level of 137 isn't out of the normal range for a singleton baby 2 weeks after embryo transfer. In fact, it's very normal and possibly indicative of just one baby. If it were in the thousands, I'd say there's a good chance she's having more. However, the fact that it nearly tripled in two days might be a better indication, but then again, 339 is a very normal level for the second HCG test as well. Unfortunately, every pregnancy is very different and there's no way to tell for sure. She'll have to wait it out until her ultrasound to find out for sure. Congrats to her, though, on successful IVF either way. And congrats to you, the future new auntie!